Powermonger takes the basic design and concepts of Bullfrog's previous game Populous, and places it in a war context. The game cast the player as a dispossessed warlord plundering his way through 195 territories on the way to world conquest. Several other leaders have the same goal.

The gameworld is now made up of polygons, so the view can be rotated and moved with greater freedom than Populous. Trade, diplomacy, inventions, and scorched earth invasions all play a key role in how the player progressed through the game. Two-player games via modem links are available on computer versions.